Various types of fluid propelling apparatuses exist. Some include reciprocating impeller panels such as the device disclosed in Smith et al., U.S. Pat. No. 1,057,891 and counter-rotating impeller panels such as the device disclosed in Immers, U.S. Pat. No. 1,532,902.
These prior devices suffer from fluid leakage between and surrounding the impeller panels, thus robbing the device of efficiency.
I propose in my U.S. patent application Ser. No. 11/518,966 filed Sep. 11, 2006 and published under U.S. Patent Application Publication No. 2008-0078860; and in my International Application No. PCT/US07/19816 filed Sep. 11, 2007 designating the U.S. and published under International Publication No. WO-2008-033398 both of which are incorporated herein by this reference, devices having counter-rotating impeller panels which remain in contact with one another during their entire rotation cycle and thus reduce leakage between the impellers.
Some potential problems with these devices include the vibrational effects of the moving lever arms, fluid leakage between contacting surfaces, and certain difficulties in maintaining synchronization between the counter rotating bodies and their drive mechanisms.
Impellers such as rotating fan blades must often rotate at high speeds in order move a given volume of fluid. Such high speed rotations can cause localized pressure variations which can adversely affect the ambient fluid or other materials suspended in the fluid. For example, high speed propellers in water craft can cause efficiency-robbing and noisy cavitations. Biological fluid samples containing sensitive chemical or biological structures can be damaged by the high speed movement of an impeller for mixing or transport.
Some existing conduits such as air conditioning conduits for large buildings or mine shafts may have rectangular, trapezoidal or other uncommon polygonal shapes that are not easily modified. It can be difficult to adapt such conduits to fans or other high speed impellers having a circular shape for moving fluid through the conduit.
The invention results from attempts to address some of the above identified problems.